Foreground-Object-Protected Depth Map Smoothing for DIBR

Depth image based rendering (DIBR) uses a 2-D color image and its associated depth map to render virtual views and then a stereoscopic image. One of the main problems in DIBR is how to reduce the size of holes in the generated virtual view image. Smoothing the depth map before image warping is a common solution. However, the previous smoothing methods bring edge distortions to the foreground objects which are more valuable than the background. In this paper, a piecewise smoothing filter is adopted, performing filtering on the depth map only in the background regions while leaving the foreground regions unchanged. And the filtering is also controlled by the registration points of the depth map. Experimental results show that the proposed method obtains better subjective qualities for the virtual views, and it is more time-saving compared to the former methods while having a better PSNR performance.